Equipment and process to finish fabrics in general

ABSTRACT

“EQUIPMENT AND PROCESS TO FINISH FABRICS IN GENERAL” comprised of a bath tank ( 3 ) that may be filled with a treatment liquid such as a bleacher, dyeing agent or washing liquid that can be adjusted to a fabric (T) conveyance means. In the circulation direction, at the rear of the bath tank ( 3 ) exit, there are squeezing rolls ( 6 ) or suction devices, to which the fabric to be squeezed or suctioned from the bath liquid is conveyed. After that there are guides on which the humid fabric may be placed on a return belt. ( 7 A). In the latter, the fabric circulates more slowly so that it is accumulatively placed on the belt ( 7 A).  
     At the end of the return belt exit ( 7 A), additional guides are connected ( 11 ) to allow the fabric (T) to return to the bath tank ( 3 ) or to allow the bath to be ended and the fabric to be taken to the plaiter unit ( 8 ).

The present invention refers to a process and to an equipment to finish fabrics in general, more specifically to prepare, wash, bleach, dye and finish fabrics products such as flat woven, tubular, Raschel, Kettenstul, crepes and other types of fabric, which can be used in market segments such as clothing, home, automotive, medical among others.

Nowadays there are different types of processes and equipment to finish fabrics in general. Among them are the discontinuous processes that work with those known as exhaustion processes. The fabric to be finished is immersed in a bath tank (water or other organic solvent) where the effective agents (bleachers, pigments, etc) migrate from the bath tank to the fabric and then to the bath, being almost entirely exhausted.

Another discontinuous process is known as Pad Batch procedure, which agents are applied by squeezing on the fabric. The product is wound in contact with those agents on a cylinder; a reaction time (up to 24 hours) should be allowed before the fabric can continue the finishing. In the Pad Steam process, the fabric goes through a steamer after being impregnated with finishing agents so that the reaction above mentioned is speeded up by thermal energy. Both processes require the fabric to be washed in other equipment after the chemical reaction. Both processes require preparation and post-treatment of the fabric, which are expensive and take time.

Despite the fact that the Pad Batch and Pad Steam processes work with relatively few water, their use is restrictive (they are not used with tubular fabrics); in reality, the so called exhaustion processes are the most significant nowadays.

An additional disadvantage of the aforementioned conventional systems lies in the fact that they are both economically and technically significant for relatively big lengths of fabric.

The biggest disadvantage of processes and equipment that use exhaustion procedures lies on the fact that the product has to constantly be immersed in the tank that contains the bath and then be exhausted again until uniformity is obtained. To obtain that, the fabric is powerfully pulled by high-speed conveyor mechanisms (up to 500 m/min) out of the bath tank on one end, being then re-immersed on the opposite end. This generates an undesirable, high fabric mechanical tension in relation to longitudinal stretching and friction on the surface (peeling), negatively affecting the quality of the end product. Usually, the fabric is not carried by the equipment in open-width form, but in rope form which leads to crease marks in more delicate fabrics. The demand of water and electrical power to apply agents and to subsequently wash them, as well as the duration of such process are much bigger.

One of the goals of the present invention is, thus, to provide a process and an equipment to finish fabrics in general that significantly reduce the demand of electricity, water, time and power.

Another goal of the present invention is to provide a process and an equipment to finish fabrics in general that reduce preparation and process costs so that they can also be economically feasible in small lengths.

Another goal of the present invention is to provide a process and an equipment to finish fabrics in general that minimizes mechanical tension, both longitudinal and on the fabric surface, to allow the finishing of extremely delicate, elastic fabrics with different grammage.

Another goal of the present invention is to provide a process and an equipment to finish fabrics in general through which fabric of different manufacturing types such as flat woven, knitted, Raschel, Kettenstul, crepes, nonwoven, etc. can be submitted to a complete wet finishing process (preparation, relaxation, dyeing, washing, rinsing, softening etc.)

Another goal of the present invention is to provide a process and an equipment to finish fabrics in general through which the finishing time and fabric processing speed are greatly reduced if compared to the traditional procedures and equipment.

Another goal of the present invention is to provide a process and an equipment to finish fabrics in general through which the fast exchange of different lots of fabric to be finished is possible with no need to modify the equipment.

Another goal of the present invention is to provide a process and an equipment to finish fabrics in general, through which lots of different sizes (between 100 and 350 kg) can be finished with no production cost changes.

The fabric is conveyed in the traditional way through the equipment as in the existent processes and equipment, and sewed in the desired length. The fabric is, thus, accumulated in the bath tank and on the conveyor belt, which results at first, in an installation of relatively smaller dimensions. Accumulation, thus, occurs in such a way that the fabric conveyance speed through the bath tank and on the conveyor belt is visibly slower as well as the entry and conveyance speeds. The fabric accumulates no the conveyor belt but is not submitted to mechanical tension.

Another advantage is that it can be done with smaller bath tanks, drastically reducing the demand of water and the respective effluent generated, between 30 and 75%.

Another advantage of the present invention resides on the fact that the fabric being processed is squeezed and/or suctioned several times so that the substrate is deposited on the return belt with defined residual humidity. This process provides a dwell time (reaction) that allows speeds lower than 80 m/min, assuring a process that is free from tension and friction.

Treatment times are equally shorter, dyeing lasts around 30 minutes, in the previous processes it used to be between 1, 5 and 2 hours.

It is possible to have a bath in almost 20 minutes, which used to take from 3 to 5 hours.

With the decrease both in the bath and treatment times one can consequently reduce power consumption.

When dyeing and/or bleaching, the excess of bath, either squeezed or suctioned, returns to the equipment bath tank; during the washing phase, such excess is discarded from the equipment.

The fabric to be immersed in the bath is conveyed by the bath itself (for example, through a circulating current.) Once the transference can be easily set, as proposed in this patent of invention, the accumulated fabric is allowed to run against a sensor. Depending on the force here applied, one sets the feeding speed of the flat fabric.

To avoid the formation of crease marks on the selvedges of the fabric, the wet fabric is conveyed on what is known as uncurling selvedge cylinder, before it is mechanically released from the bath liquid that follows it.

Mechanical squeezing may, for example, be either by suction or by squeezing with the help of rolls. The fabric previously wet is then adjusted on what is known as a centralizing device.

With the help of guides, the already squeezed fabric is conveyed on a return conveyor. The fabric is accumulated on the latter allowing dwell time, for example: 3 minutes. When previously impregnated, for example, with dyeing agents, they may react with the fibers (assembly) and simultaneously effect uniformity before they are taken to a new impregnation. Likewise, this process acts on other applications such as exhausting.

Right after removing the fabric from the conveyor belt, before new introductions to the dyeing bath tank, one measures in a reliable way the shade of the color to establish the end of the treatment which is naturally easier to do with the humid fabric than with the wet fabric.

As aforementioned, the movement of the accumulated fabric in the bath tank may, for example, take place with the help of a circulating current. The relative movement between the fabric and the bath tank, thus, promotes the transportation of the dyeing, bleaching or fiber washing means. This can also take place through the back-forward movement of the conveyor belt in which the fabric in a static bath accelerates and stops, being conveyed in an iterative way.

Likewise, the migration of the bath substances may be promoted through bath impact or through the humid fabric on the conveyor belt with vibration. The amplitude and the frequency of the size of the treatment substance particles are adjusted.

In the finishing of fabric that greatly tend to shrink, for example, this can be an advantage for elastanes. Before being introduced in the bath tank for the first time, the fabric is pre-soaked with the bath liquid so that an already shrunk fabric is introduced in the bath tank. It is, thus, necessary to provide adequate aspersor nozzles before the entry in the bath tank; they will be fed by the liquid contained in bath tank itself. Those nozzles may also be used to convey the fabric on a slide and/or rounded area at the bath tank entry, thus facilitating the accumulation of fabric.

The conveyance of the fabric accumulated in the bath tank may also be done by fluctuation on a second lower conveyor belt which may present blades or adequate profiles to facilitate the conveyance of the fabric.

The space of the return belt may optionally be enclosed, thermally conditioned and chemically controlled through the introduction of gases such a nitrogen or ozone to avoid undesirable effects.

The conveyor belt may optionally present a vibration generator to mechanically help the bath.

The equipment, according to the present invention, is then comprised of a bath tank that may be filled with a treatment liquid such as a bleacher, dyeing agent or washing liquid that can be adjusted to a fabric conveyance means.

In the circulation direction, at the rear of the bath tank exit, there are squeezing rolls to which the fabric to be squeezed or suctioned from the bath tank liquid is conveyed. After that there are guides on which the humid fabric may be placed on a return belt. The latter circulates more slowly so that the fabric is cumulatively placed on the belt.

At the end of the return belt exit, additional guides are connected to allow the fabric to return to the bath tank.

This equipment may also be found in a hermetically pressurized crankcase so that finishing is done under high pressure and temperature.

In the conveyance direction, additional guides are located at the rear of the squeezing rolls so that the finished fabric, after sewing is undone, is placed on a pallet with the help of a plaiter unit.

In the bath tank, the conveyance speed at the belt is as low as the feeding and starting speeds so that the said accumulation takes place here. To avoid the obstruction of the bath tank, there is a sensor located at its end against which the accumulated fabric touches and, depending on the force applied by the latter, the feeding speed is controlled.

The bath tank itself has, in its lower part, a base designed with a large thermal exchange area to avoid temperature variations.

A drain through which the bath liquid may be supplied to the aspersion nozzles with the help of a pump may be connected to the bath tank; those nozzles spray the bath liquid on the fabric lot to be introduced in the bath tank following the pre-shrinkage of fabric and its conveyance to the inside of the bath tank in an accumulated way.

At the bath tank entry, there is a slide and/or rounded area. Besides, the bath tank presents a conveyor belt to convey the accumulated fabric which lower portion can easily be introduced in the bath tank. The fabric floats under it and is slowly conveyed through the bath. To do that, the belt may have a blade. The conveyance means may be designed to be periodically inverted to allow iterative conveyance.

Finally, we propose a pressure variation system on the squeezing rolls, regardless of the physical characteristic of the fabric, to obtain pre-defined squeezing values (residual humidity) so that it can be placed on the return belt.

The present invention will be described below making references to the drawings enclosed in which:

FIG. 1 represents a schematic view of the equipment to finish fabric in general, more specifically for flat baths;

FIG. 2 represents another schematic view of a variation of the equipment to finish fabric in general, of a similar equipment for small fabric lots with U-shaped chute;

FIG. 3 represents another schematic view of a variation of the equipment to finish fabric in general, of a similar equipment for tilted bath for tubular fabric;

FIG. 4 represents another schematic view of a variation of the equipment to finish fabric in general, of an equipment arranged in an autoclave tank.

FIG. 1 shows a finishing equipment comprised of a structure (E) to which base a conveyor belt is (3A) placed. Below it, there is the finishing bath (3), and between them the fabric (T) to be circulated. At the equipment entry, there is a feeding, centralization and selvedges uncurling unit (1) with at least one entry cylinder (2), the latter can also be perforated, and is flanked by at least one unit of aspersors (2A), responsible for the first, fast and homogeneous impregnation of water with chemical products to be made on the fabric (T) to be finished. This fast impregnation may cause the fabric (T) to shrink before getting in touch with the said bath itself.

On the feeding, centralization and selvedge uncurling unit (1) and on the entry cylinder (2), the sewed fabric (T) is constantly supplied to the finishing bath tank where the fabric (T) is accumulated, that is, it accumulates itself.

The accumulated fabric is slowly conveyed by an adequate conveyance means through the bath tank (3), which entry is provided with a slide and/or rounded area (10) where the conveyor belt is located (3A); the fabric floats between the lower part of the belt and the bottom of the bath tank (3) and is conveyed through friction or with the help of adequate profiles. Alternatively, this may be obtained by means of a layout with one or more blades or simply through current.

The fabric at the end of the bath tank runs against a signalizer (4), which is responsible for synchronizing motion and for controlling fabric feeding (T). The feeding speed of the accumulated fabric in the bath tank can be adjusted so that the bath tank is not obstructed.

By means of guides (11), selvedges uncurling cylinders (5) and by means of a centralization device (13) that controls the deviations detected by the sensors (12), the fabric (T) gets to the squeezing rolls (6) where the excess of liquid is mechanically removed. In an impregnation process (dyeing, bleaching etc.), the squeezed fabric returns to the bath tank. In a washing process, the squeezed fabric is discarded from the equipment.

By means of additional guides (11), the fabric gets to the return belt (7A), where it is placed on a vertical tilted guide (9), that is, the conveyance speed is smaller than the speed of the flat fabric. The fabric can rest in humid condition on the extension of the return belt (7A). The clearance and the pressure between the squeezing rolls (6) can, thus, be modified. Being that possible, the fabric degree of humidity is adjusted at the exit of the roll and on the return belt (7A).

Near the entry cylinder (2) there is a set of aspersors (2A) which are connected to a piping system (17) with a pump (18) and a filter (19) connected to it.

A dyeing process in three steps—bleaching, dying and washing—was carried out in an equipment as per FIG. 1. Find below the following basic measures. The length of the bath tank was 2 m, its capacity of 600 liters, and the length of the return belt was 4 m. 300 m of towel fabric, width of 2.45 m, circulated in the equipment. The equipment was equally adjusted in the three steps; the fabric speed measured at the squeezing roll was of 50 m/min, with a remaining humidity of 70%.

The time it remained in the bath tank as well as on the return belt was of 3 minutes; 150 m of the fabric were kept in the bath tank and 150 m on the return belt. The process (preparation/dyeing/washing) was carried out with the usual means of temperature and chemicals (hydrogen peroxide, reactive dyeing agents, Remazol, detergents, etc . . . ) and the following were applied: 5 preparation cycles, 8 dying cycles, and 3 washing cycles. The total consumption of water for the three cycles together was 16.66 liters per Kg of fabric, being it substantially smaller than the technique status where numbers can almost be 110 liters per kg of fabric. The bath exchange time was 6 minutes.

FIG. 2 shows a variation of the equipment, with U-shaped chute, for small amounts of woven material.

Here, the fabric (T) is also sewed and taken to the posterior cycle by the equipment. Here, the bath tank (3) is in U-shape, and the fabric (T) accumulates when it is introduced in the bath. Conveyance through the bath tank takes place here, in a simple way, by means of gravity force. The second layer displaces the one that has already been brought with no use of signalizers.

The wet fabric (T) goes through the guides (11), the selvedges uncurling cylinder (5), and the centralization cylinders (13) to the squeezing rolls (6); from there on, it goes on the extension of the return belt (7A) where from the fabric is re-immersed in the bath tank (3). A plaiter unit (8) can be placed, again, at the equipment exit.

FIG. 3 shows a variation of the equipment with a vertical, tilted bath tank (3), the liquid circulating in the bath tank (3) chute with the fabric (T) accumulated downwards, the fabric taking that liquid with itself, continuing on the squeezing rolls (6) through the return belt (7A), as in the picture shown.

The utilization of tubular fabric is indicated for the present variation which is blown in a known way, before squeezing, with the help of blowing nozzles (14).

FIG. 4 shows the rounding of the equipment in an autoclave tank (15), where both the return belt (7A) and the bath tank (3) are rounded. The conveyance of the accumulated fabric (T) through the bath tank (3) is here done by means of an immersion cylinder (16), which presents one or more blades or similar devices and can be reverted by actuation.

The present variation, in which the return belt (7A) is almost comprised by the bath tank (3), leads to a specially small construction so that the costs of the autoclave tank (15) are reduced accordingly. In such an equipment polyester fabric can be dyed, for example, under pressure and high temperatures.

PLC-oriented sensors are provided after the squeezing rolls (6). They establish whether the fabric (T) can return to the process for one or more cycles; it is then placed on a return belt (7A) in a unit (7) foreseen in the structure (E), or taken to the extreme posterior part, to a plaiting unit (8), responsible for the processed fabric (T) withdrawal from the equipment (E).

All monitoring and general synchronism of the equipment (E) is made by capacitive sensors that guide a PLC (Programmable Logic Controller) which, in turn, commands all movements of the equipment (E) during its work cycle.

This equipment (E) is aimed at finishing fabric (T) of any kind or pattern, which are placed in cars, pallets and/or batch rolls to be introduced in the feeding, centralizing and selvedges uncurling unit (1) which represents the equipment feeding entry.

In spite of having been written and illustrated as a preferred constructive concept, it is important to point out that project changes are possible and can be carried out without changing the scope of the present invention. 

1. A process for finishing fabric characterized by the fact that fabric (T) is accumulatively conveyed in a treatment bath tank (3) and is conveyed in the bath tank itself (3) after which the fabric (T) is removed from that bath tank so that the liquid can be extracted by squeezing rolls (6) and then conveyed to a new finishing cycle through a return belt (7A), or simply end such finishing, and subsequent removal from the equipment by a plaiter unit (8).
 2. A process for finishing fabric as per claim 1, characterized by the fact that the amount of fabric (T) passing in the bath tank (3) is commanded by a signalizer (4), responsible for synchronism and motion of the fabric in the bath tank (3).
 3. A process for finishing fabric as per claim 1, characterized by the fact that the fabric (T) goes through a selvedge uncurling cylinder (5) both at the equipment entry, through a feeding unit (1) and after the bath tank (3) exit, through the selvedge uncurling cylinder (5).
 4. A process for finishing fabric as per claim 3, characterized by the fact that the excess of liquid of the bath tank (3) contained in the fabric (T) is discarded with the help of squeezing rolls (6), when the fabric (T) has gone through the selvedge uncurling cylinder (5) and the centralization device (13).
 5. A process for finishing fabric as per claim 1, characterized by the fact that the fabric (T), before the first contact with the bath itself, receives the bath liquid through aspersors (2A).
 6. A process for finishing fabric as per claim 1, characterized by the fact that the fabric (T) is introduced in the bath tank (3) through a slide and/or rounded area (10).
 7. A process for finishing fabric as per claim 1, characterized by the fact that the fabric (T) is accumulatively conveyed in the bath tank (3) and is allowed to float under the conveyor belt (3A).
 8. A process for finishing fabric as per claim 1, characterized by the fact that, optionally, the fabric (T) accumulated in the bath tank (3) can be conveyed with the help of a circulating current and/or present a back-forward movement between the fabric and the bath, which is promoted by the belt itself (3A) in which the fabric, in a static bath, accelerates and stops, being iteratively conveyed.
 9. A process for finishing fabric as per claim 1, characterized by the fact that, optionally, the bath tank (3) and/or the conveyor belt (3A) are provided with vibration.
 10. A process for finishing fabric as per claim 1, characterized by the fact that, optionally, the fabric that accumulates on the return belt (7A) is enclosed, thermally conditioned and chemically controlled through the introduction of gases in the return belt (7A) area.
 11. A process for finishing fabric as per claim 1, characterized by the fact that, optionally, the fabric (T) can be removed from the bath tank (3) so that the liquid can be extracted by means of suction devices.
 12. Apparatus for finishing fabric comprising a structure (E) provided with a bath tank (3) that is internally provided with a conveyor belt (3A) that is provided with at least one signalizer (4); provided after the belt (3A) are squeezing rolls (6) and PLC-oriented sensors that establish the end of the process or the return to one or more finishing cycles for the fabric (T); a unit (7) comprised of a return belt (7A) is foreseen and at the rear part of the equipment a plaiter unit (8).
 13. Apparatus for finishing fabric as per claim 12, characterized for presenting in its structure (E) a selvedge uncurling cylinder (5) both at the equipment entry in the feeding unit (1) and after the bath tank exit (3), through the selvedge uncurling cylinder (5).
 14. Apparatus for finishing fabric as per claim 12, characterized for being provided with a feeding unit (1) comprised of tension, centralization and selvedge uncurling cylinders, and in sequence, for being provided with at least one cylinder (2) that can be perforated and by at least one unit of aspersors (2 a).
 15. Apparatus for finishing fabric as per claim 12, characterized for being provided with general monitoring and synchronism carried out by capacitive PLC-oriented sensors which, in turn, command all equipment movement during its work cycle.
 16. Apparatus for finishing fabric as per claim 12, characterized by the fact that the entry of the bath tank (3) is provided with a slide and/or rounded area (10).
 17. Apparatus for finishing fabric as per claim 12, characterized by the fact that, optionally, the bath tank (3) and/or conveyor belt (3A) present a vibration generator.
 18. Apparatus for finishing fabric as per claim 12, characterized by the fact that, optionally, the fabric (T) conveyance means or conveyor belt (3A) present one or more blades or adequate profiles to convey the fabric.
 19. Apparatus for finishing fabric as per claim 12, characterized for the lower part of bath tank (3) being provided with a heat exchanger.
 20. Apparatus for finishing fabric as per claim 12, characterized for, optionally, presenting a pressure variation system on the squeezing rolls (6) so that, regardless of the physical characteristic of the fabrics, one can obtain pre-defined squeezing values (residual humidity).
 21. Apparatus for finishing fabric as per claim 12, characterized by the fact that, optionally, the conveyance of the fabric (T) accumulated in the bath tank (3) may also be done by fluctuation on a second lower conveyor belt which may present one or more blades or adequate profiles to facilitate the conveyance of the fabric.
 22. Apparatus for finishing fabric comprising a structure (E) that is provided with a bath tank (3), squeezing rolls (6) or and PLC-oriented sensors that establish the end of the process or the return to one or more fabric (T) finishing cycles, where a return belt (7A) is foreseen and a plaiter unit (8) at the extreme end of the equipment.
 23. Apparatus for finishing fabric as per claim 22, comprising, at the equipment entry, a feeding unit (1) and after the bath tank (3), selvedge uncurling cylinders (5), squeezing rolls (6) and guides (11).
 24. Apparatus for finishing fabric comprising a structure (E) that presents a vertical tilted bath tank (3) provided with a belt (3A), after which squeezing rolls (6) and PLC-oriented sensors are located; the latter establishes the end of the process or the return to one or more finishing cycles for the fabric (T); a return belt (7A) is foreseen and at the extreme end of the equipment a plaiter unit (8).
 25. Apparatus for finishing fabric as per claim 24, comprising a feeding unit (1) at the equipment entry and squeezing rolls (6) after the bath tank (3).
 26. Apparatus for finishing fabric as per claim 24, characterized for being provided with blowing nozzles (14), to blow tubular fabric, before the squeezing rolls (6).
 27. Apparatus for finishing fabric comprising a structure (E) in autoclave tank form (15) that presents a bath tank (3) and a return belt (7A) in rounded shape, comprising an immersion cylinder (16), after which one will find squeezing rolls (6) and PLC-oriented sensors that establish the end of the process or the return to one or more fabric (T) finishing cycles, where a return belt (7A) is foreseen and a plaiter unit (8) at the extreme end of the equipment.
 28. Apparatus for finishing fabric as per claim 27, characterized for presenting in its structure (E) a selvedge uncurling cylinder (5) both at the equipment entry, in the feeding unit (1), and after the bath tank exit (3), through the selvedge uncurling cylinder (5).
 29. Apparatus for finishing fabric as per claim 27, characterized by the fact that, optionally, structure (E) is provided with suction devices (6) after the belt (3A). 